Methods, systems, and devices for controlling anti-sweat heaters

ABSTRACT

The various embodiments disclosed herein relate to anti-sweat heater systems for refrigeration units. More specifically, certain embodiments relate to anti-sweat heater control systems having one or more controllers that operate anti-sweat heaters independently of each other.

FIELD OF THE INVENTION

The various embodiments disclosed herein relate to anti-sweat heatersystems for refrigeration units. More specifically, certain embodimentsrelate to anti-sweat heater control systems having one or morecontrollers that operate anti-sweat heaters independently of each other.

BACKGROUND OF THE INVENTION

Anti-sweat heaters are used to reduce, prevent, or eliminatecondensation on the doors, frame, and mullions of refrigeration unitssuch as the large commercial refrigeration units found in grocerystores. As condensation forms on the doors (and windows in the doors),frame, and mullions of a refrigeration unit, various known heatersystems operate to eliminate that condensation. The known systemstypically have a single controller that is coupled to all the heatersassociated with a refrigeration unit such that the controller can onlyactivate or de-activate all of the heaters at once (it cannot activateany heaters individually).

There is a need in the art for improved anti-sweat heater systems.

BRIEF SUMMARY OF THE INVENTION

One embodiment disclosed herein relates to a system for controllinganti-sweat heaters having a controller, at least one door heater, afirst door moisture sensor, at least one frame/mullion heater, and afirst frame/mullion moisture sensor. The controller has a door channeland a frame/mullion channel that is independent of the door channel. Thefirst door moisture sensor is operably coupled to the controller andconfigured to transmit a door sensor resistance reading to thecontroller. The first frame/mullion moisture sensor is operably coupledto the controller and configured to transmit a frame/mullion sensorresistance reading to the controller.

Another embodiment relates to a system for controlling anti-sweatheaters having a first controller, at least one first door heater, afirst door moisture sensor, at least one first frame/mullion heater, afirst frame/mullion moisture sensor, a second controller, at least onesecond door heater, a second door moisture sensor, at least one secondframe/mullion heater, and a second frame/mullion moisture sensor. Thefirst controller has a first door channel and a first frame/mullionchannel that is independent of the first door channel. The first doormoisture sensor is operably coupled to the first controller andconfigured to transmit a first door sensor resistance reading to thefirst controller. The first frame/mullion moisture sensor is operablycoupled to the first controller and configured to transmit aframe/mullion sensor resistance reading to the first controller. Thesecond controller is independent of the first controller and has asecond door channel and a second frame/mullion channel that isindependent of the second door channel. The second door moisture sensoris operably coupled to the second controller and configured to transmita second door sensor resistance reading to the second controller. Thesecond frame/mullion moisture sensor is operably coupled to the secondcontroller and configured to transmit a second frame/mullion sensorresistance reading to the second controller.

A further embodiment relates to a system for controlling anti-sweatheaters. The system has a controller, at least one door heater, a firstdetachable door moisture sensor, at least one frame/mullion heater, anda first detachable frame/mullion moisture sensor. The controller has adoor channel and a frame/mullion channel that is independent of the doorchannel. The first detachable door moisture sensor is operably coupledto the controller, is configured to transmit a door sensor resistancereading to the controller, and is powered with AC current. The firstdetachable frame/mullion moisture sensor is operably coupled to thecontroller, is configured to transmit a frame/mullion sensor resistancereading to the controller, and is powered with AC current. Thecontroller is configured to activate the at least one door heater whenthe door sensor resistance reading reaches a predetermined level and isfurther configured to activate the at least one frame/mullion heaterwhen the frame/mullion sensor resistance reading reaches a predeterminedlevel. In addition, the controller is configured to perform a programmedmaintenance cycle.

While multiple embodiments are disclosed, still other embodiments of thepresent invention will become apparent to those skilled in the art fromthe following detailed description, which shows and describesillustrative embodiments of the invention. As will be realized, theinvention is capable of modifications in various obvious aspects, allwithout departing from the spirit and scope of the present invention.Accordingly, the drawings and detailed description are to be regarded asillustrative in nature and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of an anti-sweat heater control systemincorporated into a refrigeration unit, according to one embodiment.

FIG. 2 is a perspective view of a controller, according to oneembodiment.

FIG. 3 is a perspective view of a door sensor and a frame/mullion sensorpositioned on a refrigeration unit, according to one embodiment.

FIG. 4A is a front view of a sensor, according to one embodiment.

FIG. 4B is a front view of the electrical component of the sensor ofFIG. 4A.

FIG. 4C is a side view of the sensor of FIG. 4A.

FIG. 5 is a perspective view of sensor, according to another embodiment.

DETAILED DESCRIPTION

The various embodiments disclosed herein relate to methods, systems, anddevices for controlling anti-sweat heaters associated with various typesof commercial refrigeration and freezer units having glass display doors(doors with large display windows). Certain embodiments herein relate toa control component that is configured to control at least one doorheater separately and independently from any frame heaters and/ormullion heaters. In other system and device implementations, a moisturesensor is provided that is strategically placed on an outer surface ofthe door frame at a predetermined location where condensation initiallyoccurs when the door heater is not operating. In alternative aspects inwhich there is more than one refrigeration/freezer unit (and thus morethan one set of heaters), there is a controller provided for eachseparate unit, such that each separate controller is associated withonly one unit and is operably coupled to only the sensors and heatersassociated with that unit, rather than a single controller being coupledin series to sensors and heaters on more than one unit.

Generally, the embodiments disclosed herein relate to systems or methodsfor reducing or preventing condensation on the external surfaces of arefrigeration/freezer unit. Anti-sweat heaters are used to reduce,prevent, or eliminate that condensation. The various embodimentsdisclosed herein have a controller that will turn the anti-sweat heaterson and off and only allow the heaters to come on when needed, thuseliminating wasted energy while preventing condensation or frost fromforming on the outside of the refrigeration case and/or glass displaydoors.

According to one embodiment, the systems and devices herein have twosets of heaters that are installed on a commercial refrigeration case.The first set of heaters typically supplies heat to the glass displaydoors. These heaters are generally called “door heaters” and they supplyheat to only the actual door(s) or more specifically to the displayglass in the door(s). The second set of heaters typically supplies heatto the frame (the framework around the area where the door is mounted)and mullions (the vertical supports between the doors) of the displaycase. In this embodiment, the controller controls the door heatersseparately from the frame and mullions heaters as described in furtherdetail below. Alternatively, the systems and devices herein includethree sets of heaters, including the door heaters and separate sets offrame heaters and mullion heaters. In this alternative embodiment, thecontroller still controls the door heaters separately from the frameheaters and the mullion heaters.

FIG. 1 depicts an anti-sweat heater control system incorporated into arefrigeration unit 10, according to one embodiment. The system has acontroller 12 that is coupled to the door sensor 14 via a wire 16.Separately, the controller 12 is also coupled to the mullion and framesensor 18 via a wire 20.

The sensor(s) and heaters for the doors are controlled separately andindependently of the sensor(s) and heaters for the mullions and/orframe. That is, there is a “channel” provided for the door sensor(s) andthe door heaters of a unit (such as the unit 10 depicted in FIG. 1), andthere is a separate “channel” provided for the frame and/or mullionsensor(s) and the frame and/or mullion heaters of the unit. The word“channel” is used herein to indicate that the operable coupling of thecontroller to the door sensor(s) and heaters is separate and independentfrom the operable coupling of the controller to the frame and/or mullionsensor(s) and heaters.

FIG. 2 depicts the inputs of a controller 40, according to oneembodiment. In this embodiment, the controller 40 has two channels: adoor sensor/heater channel 42 and a frame/mullion sensor/heater channel44. In this embodiment, the door sensor/heater channel 42 has two inputs42A, 42B that are configured to receive the appropriate connections tothe door sensor(s) (not shown). In this embodiment, the controller 40 iscoupled to only one door sensor, which has a connection received atinput 42A. Similarly, the frame/mullion sensor/heater channel 44 has twoinputs 44A, 44B that are configured to receive the appropriateconnections to the frame and/or mullion sensor(s) (not shown). In thisembodiment, the controller 40 is coupled to only one frame and/ormullion sensor, which has a connection received at input 44B.

Returning to FIG. 1, the door sensor 14 is positioned strategicallyalong the side of the door 22C in the location where it has beendetermined that condensation first forms on that door 22C. In thisparticular embodiment, the sensor 14 is positioned near the bottom ofthe side of the door 22C that is hinged to the frame of the unit 10.Alternatively, the door sensor 14 can be removably positionable orattachable anywhere on an external surface of any of the doors 22A, 22B,22C such that a user or employee of the supermarket, the manufacturer ormarketer of the system, or any other appropriate enterprise can adjustthe location of the sensor 14, thereby positioning that sensor 14 in theoptimal location at which condensation first forms on the door or doorsof that particular unit 10.

Alternatively, more than one door sensor can be provided according tovarious embodiments herein. In such an implementation, the two or moresensors can be positioned on the same door of the unit or can bepositioned on different doors.

Like the door sensor 14, the frame/mullion sensor 18 is also positionedstrategically on an external surface of the frame 24 or mullions 26 ofthe unit 10 in the location where it has been determined thatcondensation first forms on the frame 24 and/or mullions 26. In thisparticular embodiment, the sensor 18 is positioned near the bottom ofthe mullion 26A. Alternatively, the frame/mullion sensor 18 can beremovably positionable or attachable anywhere on an external surface ofany portion of the frame 24 or mullions 26A, 26B such that a user oremployee can adjust and thereby optimize the location of the sensor 18.In a further alternative, more than one frame/mullion sensor can beprovided. In such an implementation, the two or more sensors can bepositioned anywhere on the frame 24 or mullions 26A, 26B of the unit 10.

According to another implementation as set forth in FIG. 3, a doorsensor 50 is positioned on the edge of a door 54 and a frame/mullionsensor 52 is positioned on the mullion 56 as shown.

It is understood that the door sensor 14 is electrically connected(through the controller 12) to the heaters (not shown) that areassociated with the doors of the unit 10. More accurately, thecontroller 12 is operably coupled to the door sensor 14 and to theheaters such that the sensor 14 and heaters are coupled to each other.Similarly, the controller 12 is operably coupled to the frame/mullionsensor 18 and to the frame/mullion heaters such that the sensor 18 andheaters are coupled to each other. It is further understood that theheaters are provided in the refrigeration/freezer unit in anyconfiguration that is known in the art. Generally, the heaters areintegrated into the structure of each door and into the frame andmullions.

Even though the controller 12 in FIG. 1 is depicted schematically asbeing positioned at a location away from the refrigeration unit, it isunderstood that this is simply a schematic representation. In oneembodiment, the controller is positioned under the refrigeration unit 10and behind the lower panel 28. Alternatively, the controller can bepositioned anywhere on the unit 10 or even at some distance from theunit 10.

It is understood that the controller 12 is not only coupled to thesensors and heaters as shown according to one configuration in FIG. 1,but it is also coupled to the power supply. In a further embodiment, thecontroller 12 is also coupled to a ground wire.

In various embodiments, more than one refrigeration/freezer unit isprovided. In these embodiments, a separate controller is provided foreach unit, in which each such controller is coupled to the sensors andheaters of the unit to which that controller is associated. Thus, inthese implementations, the sensors of the multiple units are not coupledto each other in series along a single wire and ultimately to a singlecontroller. Instead, the sensors of each individual unit are coupledsolely to the controller associated with that unit.

According to one implementation, each of the sensors 14, 18 are moisturesensors that are configured to detect moisture. FIGS. 4A, 4B, and 4Cdepict a sensor 60 for use with the various embodiments disclosedherein, according to one implementation. FIGS. 4A and 4B depict frontviews of the sensor 60, while FIG. 4C is a side view of the sensor 60.According to one embodiment, the sensor 60 has a generally oval shape asshown such that the width of the face of the sensor is reduced incomparison to other known sensors, thereby allowing the sensor to bepositioned in narrower spaces than can be accomplished with the widerknown sensors.

FIG. 5 depicts another embodiment of a sensor 70. This sensor 70 has asensor connector 72 that allows the sensor 70 to be coupled to a wireconnector 74 on the wire 76. In one implementation, this sensor 70 withits connector 72 allows for easy coupling to and uncoupling from thesystem, thereby providing for easy repair, replacement, or relocation ofany such sensor 70 in the system. According to another embodiment, thecoupling of the sensor connector 72 to the wire connector 74 can providea stronger connection between the wire 76 and the sensor 70. That is,the connectors 72, 74 can provide a stronger physical connection than asimple solder connection of the wire to the sensor such that theconnection between the wire 76 and the sensor 70 can withstand morephysical stress or strain without disconnecting.

According to one implementation, each moisture sensor is a multi-metalsensor. In a further alternative, it is understood that any moisturesensor known in the art could be used with the various embodimentsdisclosed herein. For example, any of the sensors disclosed in U.S. Pat.No. 5,899,078 or 7,240,501 (both of which are hereby incorporated hereinby reference in their entireties) can be used in any of the embodimentsherein.

In accordance with one embodiment, each of the sensors operate using ACcurrent and continually transmit a resistance reading to the controller.More specifically, using FIG. 1 as an example, the controller 12provides a constant AC current to the sensors 14,18 and continuallymonitor the resistance readings provided by each of the sensors 14,18.When the heaters are off, the outside of the refrigeration unit willbegin to cool. At some point, condensation will begin to form on theoutside of the refrigeration case. As the condensation forms on each ofthe sensors 14, 18, that impacts the resistance readings sent to thecontroller 12 by each of those sensors 14, 18. When the resistancereading from either sensor 14 or 18 reaches a specific predeterminedlevel (which is adjustable), the controller activates the heatersassociated with that sensor, while the other, unlinked heaters are notactivated until their sensors are separately triggered by condensation.For example, if the door sensor 14 has a resistance reading that reachesthe predetermined level due to condensation forming around or on thesensor 14, the controller 12 activates the door heaters for that unit,while the frame and/or mullion heaters are not activated. When theresistance of the door sensor 14 has recovered (reversed) as a result ofthe door heaters reducing or eliminating the condensation, the doorheaters will then be deactivated and put into an “off” state. Thisprocedure is followed for the frame/mullion sensors 18 and theframe/mullion heaters as well.

One unexpected benefit of using AC current to power the sensorsaccording to one embodiment, is that it can prevent or reduce problemswith sensor sensitivity or failure. Known systems utilize DC current topower their sensors. When multi-metal sensors are used, the DC currentcan cause ion buildup on the sensors, often resulting in impaired sensorsensitivity and in many cases sensor failure. The use of AC currenteliminates the ion buildup, thereby reducing the problems withsensitivity and failure.

In an embodiment in which each channel has more than one input (isconnected to more than one sensor, such as the controller depicted inFIG. 2, for example), either sensor can trigger activation of theheater. That is, the appropriate predetermined level of resistance doesnot need to be reached at both sensors in order to trigger activation ofthe heater—either sensor can trigger activation individually.

One benefit of having separate channels for the separate sensor-heatercombinations is efficiency. That is, only the appropriate heater for theactual condensation is activated, while heaters attached to doors orcomponents without condensation are not activated. In known technologiescurrently on the market, condensation triggers multiple heaters to beactivated, including heaters that are not associated with a componentthat is currently experiencing condensation, thereby resulting inwasteful consumption of energy.

According to one implementation, a controller such as the controller 12in FIG. 1 can also be programmed to include an automatic maintenancecycle. The controller 12 with this programmed maintenance cycle willautomatically activate one or more of the heaters to operate for apredetermined amount of time. In one example, the controller 12 isprogrammed to activate each door heater channel and each frame/mullionheater channel for 15 minutes during every three hour period.Alternatively, the controller 12 can be programmed to activate everyheater for any amount of time during any time period. In one embodiment,the programmed maintenance cycle causes each heater to be activatedseparately such that the heaters are not activated at the same time.That is, the various heaters can be activated at different times by thecontroller. In one implementation, the heaters are activated atdifferent times to capture significant demand (kW) savings on the heaterload. The programmed maintenance cycle prevents each of the heaters frombeing un-activated for extended periods of time, which can lead tomoisture or ice buildup in areas that are not visible from outside thedisplay case and/or areas where there is no moisture sensor, such asdoor gaskets, mullion chambers, electrical raceways, etc.

Although the present invention has been described with reference topreferred embodiments, persons skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

What is claimed is:
 1. A system for controlling anti-sweat heaters,comprising: (a) a controller comprising: (i) a door channel comprisingat least one door channel input; and (ii) a frame/mullion channelcomprising at least one frame/mullion channel input, wherein theframe/mullion channel is independent of the door channel; (b) at leastone door heater operably coupled to the door channel; (c) a first doormoisture sensor configured to be positioned on a refrigeration casedoor, the sensor operably coupled to the controller at the at least onedoor channel input, the first door moisture sensor configured totransmit a door sensor resistance reading to the controller; (d) atleast one frame/mullion heater operably coupled to the frame/mullionchannel; and (e) a first frame/mullion moisture sensor configured to bepositioned on a frame or mullion, the sensor operably coupled to thecontroller at the at least one frame/mullion channel input, the firstframe/mullion sensor configured to transmit a frame/mullion sensorresistance reading to the controller.
 2. The system of claim 1, whereinthe controller is configured to activate the at least one door heaterwhen the first door moisture sensor resistance reading reaches apredetermined level and is further configured to activate the at leastone frame/mullion heater when the first frame/mullion moisture sensorresistance reading reaches a predetermined level,
 3. The system of claim1, wherein the controller is configured to transmit AC current to thefirst door moisture sensor and the first frame/mullion moisture sensor.4. The system of claim 1, wherein the controller is further configuredto perform a programmed maintenance cycle.
 5. The system of claim 4,wherein the programmed maintenance cycle comprises a predeterminedactivation of at least one of the at least one door heater and the atleast one frame/mullion heater by the controller for a predeterminedamount of time during each predetermined period of time.
 6. The systemof claim 5, wherein the predetermined amount of time is 15 minutes andthe predetermined period of time is three hours.
 7. The system of claim5, wherein the predetermined activation of the at least one door heateris independent of the predetermined activation of the at least oneframe/mullion heater.
 8. A system for controlling anti-sweat heaters,comprising: (a) a first controller comprising: (i) a first door channelcomprising at least one first door channel input; and (ii) a firstframe/mullion channel comprising at least one first frame/mullionchannel input, wherein the first frame/mullion channel is independent ofthe first door channel; (b) at least one first door heater operablycoupled to the first door channel; (c) a first door moisture sensorconfigured to be positioned on a first refrigeration case door, thefirst door moisture sensor operably coupled to the first controller atthe at least one first door channel input, the first door moisturesensor configured to transmit a first door sensor resistance reading tothe first controller; (d) at least one first frame/mullion heateroperably coupled to the first frame/mullion channel; (e) a firstframe/mullion moisture sensor configured to be positioned on a firstrefrigeration case frame or mullion, the first frame/mullion moisturesensor operably coupled to the first controller at the at least onefirst frame/mullion channel input, the first frame/mullion sensorconfigured to transmit a first frame/mullion sensor resistance readingto the first controller; (f) a second controller independent of thefirst controller, the second controller comprising: (i) a second doorchannel comprising at least one second door channel input; and (ii) asecond frame/mullion channel comprising at least one secondframe/mullion channel input, wherein the second frame/mullion channel isindependent of the second door channel; (g) at least one second doorheater operably coupled to the second door channel; (h) a second doormoisture sensor configured to be positioned on a second refrigerationcase door, the second door moisture sensor operably coupled to thesecond controller at the at least one second door channel input, thesecond door moisture sensor configured to transmit a second door sensorresistance reading to the second controller; (i) at least one secondframe/mullion heater operably coupled to the second frame/mullionchannel; and (j) a second frame/mullion moisture sensor configured to bepositioned on a second refrigeration case frame or mullion, the secondframe/mullion moisture sensor operably coupled to the second controllerat the at least one second frame/mullion channel input, the secondframe/mullion sensor configured to transmit a second frame/mullionsensor resistance reading to the second controller.
 9. The system ofclaim 8, wherein the first controller is configured to activate the atleast one first door heater when the first door moisture sensorresistance reading reaches a predetermined level and is furtherconfigured to activate the at least one first frame/mullion heater whenthe first frame/mullion moisture sensor resistance reading reaches apredetermined level,
 10. The system of claim 8, wherein the secondcontroller is configured to activate the at least one second door heaterwhen the second door moisture sensor resistance reading reaches apredetermined level and is further configured to activate the at leastone second frame/mullion heater when the second frame/mullion moisturesensor resistance reading reaches a predetermined level.
 11. The systemof claim 8, wherein the first controller is configured to transmit ACcurrent to the first door moisture sensor and the first frame/mullionmoisture sensor, and further wherein the second controller is configuredto transmit AC current to the second door moisture sensor and the secondframe/mullion moisture sensor.
 12. The system of claim 8, wherein thefirst controller is further configured to perform a first programmedmaintenance cycle and the second controller is further configured toperform a second programmed maintenance cycle.
 13. The system of claim12, wherein the first programmed maintenance cycle comprises apredetermined activation of at least one of the at least one first doorheater and the at least one first frame/mullion heater by the firstcontroller for a predetermined amount of time during each predeterminedperiod of time.
 14. The system of claim 12, wherein the secondprogrammed maintenance cycle comprises a predetermined activation of atleast one of the at least one second door heater and the at least onesecond frame/mullion heater by the second controller for a predeterminedamount of time during each predetermined period of time.
 15. A systemfor controlling anti-sweat heaters, comprising: (a) a controllercomprising: (i) a door channel comprising at least one door channelinput; and (ii) a frame/mullion channel comprising at least oneframe/mullion channel input, wherein the frame/mullion channel isindependent of the door channel; (b) at least one door heater operablycoupled to the door channel; (c) a first detachable door moisture sensorconfigured to be positioned on a refrigeration case door, the sensoroperably coupled to the controller at the at least one door channelinput, the first door moisture sensor configured to transmit a doorsensor resistance reading to the controller, wherein the firstdetachable door moisture sensor is powered with AC current; (d) at leastone frame/mullion heater operably coupled to the frame/mullion channel;and (e) a first detachable frame/mullion moisture sensor configured tobe positioned on a frame or mullion, the sensor operably coupled to thecontroller at the at least one frame/mullion channel input, the firstframe/mullion sensor configured to transmit a frame/mullion sensorresistance reading to the controller, wherein the first detachableframe/mullion moisture sensor is powered with AC current, wherein thecontroller is configured to activate the at least one door heater whenthe door sensor resistance reading reaches a predetermined level and isfurther configured to activate the at least one frame/mullion heaterwhen the frame/mullion sensor resistance reading reaches a predeterminedlevel, wherein the controller is further configured to perform aprogrammed maintenance cycle.
 16. The system of claim 15, wherein theprogrammed maintenance cycle comprises separately activating the atleast one door heater and the at least one frame/mullion heater tooperate for a predetermined amount of time during a predetermined periodof time.
 17. The system of claim 16, wherein the programmed maintenancecycle further comprises separately activating the at least one doorheater and the at least one frame/mullion heater at different times. 18.The system of claim 15, wherein the activation of the at least one doorheater by the controller is independent of the activation of the atleast one frame/mullion heater by the controller.
 19. The system ofclaim 15, wherein the activation of the at least one door heater by thecontroller comprises activation of the door channel and further whereinthe activation of the at least one frame/mullion heater by thecontroller comprises activation of the frame/mullion channel.
 20. Thesystem of claim 19, wherein the frame/mullion channel is independent ofthe door channel such that the activation of the frame/mullion channelis independent of the activation of the door channel.